Air to air heat pump apparatus



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AIR TO AIR HEAT PUMP APPARATUS Filed eb. 15, 1954 7 sheets-sheet 2 Nov. 13, 1956 R. H. BURGEss 2,770,107

` AIR T0 AIR HEAT PUMP APPARATUS Filed Feb. 15, 1954 7 Sheets-Sheet 3 PIE. El

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AIR TO AIR HEAT PUMP APPARATUS Filed Feb. 15,- 1954 7 Sheets-Sheet 4 [ha] m Nov. 13, 1956 R. H. BURGESS 2,770,107

AIR To AIR HEAT PUMP APPARATUS Filed Feb. 15, 1954 7 sheets-sheet 5 Nov. 13, 1956 R. H. BURGl-:ss

AIR T0 AIR HEAT PUMP APPARATUS 7 Sheets-Sheet 6 Filed Feb. 15, 1954 Nov. 13, 1956 R. H. BURGESS Filed Feb. 15, 1954 7 Sheets-Sheet 7 FIE- V,

46] l il L25 162* 15M 's 16o I T/ 245 f j 2,4/1@ Z4 .A /05-5 1r j. Zs-Z Jaa Z55 /45 A A l fafa 256 zZ-Z22 za/z Z0! ZOE United States Patent O AIR TO AIR HEAT PUMP APPARATUS Russell H. Burgess, Chicago, lll., assignor to Drying Systems, Inc., Chicago, lll., a corporation of Illinois ApplicationFebruary 15, 1954, Serial No. 410,203

4 Claims. (Cl. 62-117.S)

This invention relates to air-to-air heat pump apparatus.

Air-to-air heat pump apparatus finds its greatest eld of use in residence installations or in other locations where excessive noise is highly objectionable, and despite the well recognized fact that the objectionable noise has its source in the compressor, and to a slight extent in the compressor motor, no way has been found heretofore for reducing such noise to a tolerable level.

It is therefore the primary object of the present invention to reduce the compressor and motor noise in heat pump apparatus of the aforesaid character, and to accomplish this in a simple and inexpensive manner. More specifically, it is an object of the present invention to reduce the noise in such apparatus in a way that enables refrigerant systems to effectually utilize the heat produced by the motor and the compressor in the attainment of the desired heating operation of the apparatus.

More specifically stated, it is an object of the present invention to house the compressor and its driving motor in an insulated -chamber thereby to confine the noise as well as `the heat produced by the motor and the compresser, and to dissipate such heat through the use of a superheater in the refrigerant system, thereby to effectually utilize this heat which would otherwise be wasted, while at the same time to improve the performance of the compressor means due -to the superheating of the gas refrigerant.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show a preferred embodiment of the present invention and the principles thereof and what I now .consider to be the best mode in which I have contemplated applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

Fig. 1 is a side elevational view taken partially in vertical section and illustrating a heat pump apparatus embodying the features of the invention;

Fig. 2 is a view taken from the left in Fig. l and showing details of internal construction of the apparatus;

Fig. 3 is a view similar to Fig. 2 and showing additional details;

Fig. 4 is a fragmentary perspective View showing the sump and related parts of the base;

Fig. 5 is a sectional view taken substantially along the line 5 5 of Fig. 4;

Fig. 6 is a sectional view taken substantially along the line 6 6 of Fig. 4;

Fig. 7 is a schematic view illustrating the refrigerant circuit;

2,770,107 Patented Nov. 13, 1956 Fig'. 8 lis a perspective view illustrating further details of the refrigerant circuit; and

Fig. 9 is a wiring diagram illustrating the electrical control circuit of the invention.

peicey General organization For purposes of disclosure, the invention is herein illustrated as embodied lin an air `to air heat pump apparatus 20 that is sectionalized in its physical structure so as to facilitate transportation and installation. Thus, the heat pump 20 comprises a relatively at base unit 21, a blower unit 22 that rests on and completely covers the base unit 21, a compressor and heat exchange unit 23 that rests on and completely covers the unit 22, and an upper duct unit 24 that rests upon the unit 23, and these sections or units may be secured in such relation by conventional fastening means such as screws, bolts or the like. The units 21, 22, 23 and 24 are so formed and related, as will be described in detail hereinafter, that a generally U-shaped inside air passage 25 is provided including heat exchangers 26 and 27, and a generally U- shaped outside air passage 28 including heat exchangers 29 and 30 is provided. As will be hereinafter explained, the present apparatus may be set selectively for winter operation or summer operation, and in the winter setting of the apparatus the heat exchangers 27 and 26 act' as a common condenser in the refrigerant circuit, while the heat exchangers 30 and 29 in the outside air circuit act as a common evaporator. Conversely, in the summer setting of the apparatus, the heat exchangers 27 and 26 in the inside air circuit act as evaporators so as to cool the air in the inside air cincuit, while the heat exchangers 30 and 29 in the outside air circuit serve as a common condenser to dissipate heat to the air flowing in the outside air circuit.

The individual sections or units The base 21 is formed primarily by two end channels 31 and two side channels 32 secured together so that they rest on edge and define a rectangle. Midway between the side channels 32 and parallel thereto, an elongated pan or sump 33 is mounted in fixed relation to the end channels 31, and throughout a substantial portion of its length the pan 33 is ofthe same depth as the base, as shown in Fig. l, while throughout the balance of its length the bottom of the pan slopes upwardly so that it will drain toward the deep end. Within the sloping end portion of the pan 33 a central division wall is formed by an inverted U-shaped member 33P that has its lower edges fixed to the bottom wall of the pan and which has v its closed upper end disposed in the plane of the upper edges of the channels 31 and 32. At the left hand end of the member 33P, Fig. 4, a cross plate 33E is extended across the pan 33 with its upper edge in the plane of the upper edges of the channels 31 and 32, and its lower n edge spaced from the bottom of the pan 33 below the normal level of water that is maintained in the sump or pan 33, as will be explained hereinafter.

The unit 22 is afforded by a plurality of square tubular frame members 39 on which parallel end walls 40 and 41 and an intermediate wall 42 are supported, the interme- `1 diate wall 42 being spaced from the end wall 40 so that the wall 40 is afforded by doors which extend the full height of the sections 22, 23 and 24 so that these doors or walls 40 form the front or left-hand wall in Fig. l, for all of the units. The unit 22 is thus divided into a pump chamber 48 defined by the Walls 40, 42 and 46, an inside fan'chamber 49 defined by the walls 41, 42, 46 and 47, and an outside fan chamber 50 defined by the walls 41, 42, 47 and 45.

Within the pump chamber 48 a water pump 51 is supported with an intake pipe 51? projecting downwardly into the sump 33. This pump 31 is driven by a motor 51M, and itsY discharge passes through a pipe 51D to its point of use, as will be described hereinafter.

Within the inside fan chamber 49, an inside blower or fan 52 is mounted on support bars 52B, so that the discharge 52D -of the fan opens upwardly adjacent to the wall 47. Similarly, an outside blower or fan 53 is mounted on supports 53B in the chamber 50 so that the discharge 53D is directed upwardly adjacent to the other side of the wall 47. The fans 52 and 53 are driven by belt connections from drive motors 52M and 53M that are supported from cross bars 52B and 53B in the chambers 49 and 50 of the unit 22. The chambers 49 and 50 constitute portions of the respective inside and outside air passages 25V and 28 and cooperating portions of these passages are formed in part in the unit 23 and in part in the unit 24, as will now be described.

The unit 23 also has a framework formed from square tubular members 59 closed at its forward end by the Wall afforded by the doors 40 and on which an end wall 61 and an intermediate wall 62 are mounted in parallel relation, so that the intermediate wall 62 is substantially above the wall 42. The unit 23 has side walls 65 and 66, and between the wall 62 and the end wall 61, a thick insulating wall 67 is mounted so as to rest on and form an upward continuation of the wall 47. Midway between the walls 66 and 67 a vertical division wall 68 is extended parallel to the walls 66 and 67 thus to afford a downward passage 25D between the walls 66 and 68, and an upward passage 25U between the walls 68 and 67. Similarly, a wall 69 is mounted midway between and parallel to the walls 65 and 67 to define a downward passage 28D between the walls 65 and 69 and an upward passage 28U between the walls 67 and 69. In the lower end portion of the passage 28D, the heat exchanger 29 is mounted; in the upper end of the passage 28U the heat exchanger 30 is mounted; in the lower end of the passage 25D, the heat exchanger 26 is mounted; while in the upper end portion of the passage 25D, the heat exchanger 27 is mounted;l and these heat exchangers function in the operation of the heat pump system, as will be hereinafter described. Above the. heat exchanger 29 and in the passage 28D, a spray nozzle 75 is mounted and is connected to the discharge 51D of the water pump 51 so that the heat exchanger 29 may be caused to function as an evaporative condenser, as will be described.

The passages 25U and ZSU have their lower ends partially closed by cross walls 68W and 69W, each of which has a relatively large opening therein, these openings being connected to the respective discharge ends of the fans 52 and 53 by flexible sleeves 52F and 53F.

The space defined by the walls 40, 62, 65 and 66 constitutes a compressor chamber 80 and has bottom and top walls 81 and 82 so as to constitute a closed chamber, and since the doors 40 may beV opened at Will, an inside stationary wall 60 is provided just inside the doors 40. The wall 60, as well as all of the other Walls defining the compressor chamber 80, are lined with sound absorbent material so as to eliminate objectionable noise transmission, and these walls are so tted wit-h respect to each other as to prevent air circulation into and out of the chamber 80. Such sound insulation also serves as heat insulation so that the heat of the compressors is confined to the chamber 80 for effective use in the heating cycle of the present system. Within the compressor chamber 80,

first and second motor driven compressors C-l and C-2 are mounted, along with a considerable portion of the refrigerant piping and control means including a four-way control valve 84 and a suction gas superheater afforded by a heat exchanger 85 suspended above the compressors C-l and C-2 and functioning as will be described hereinafter to dissipate and effectually utilize the heat of the compressors.

The upper unit 24 of the structure is afforded by a framework made from square tubular members 89 having its forward end closed by the walls or doors 40 and having an end wall 91 and an intermediate wall 92 which falls substantially in the plane of the wall 62. Side walls 95 and 96 are also provided and between these side walls a heavy insulated division wall 97 is provided which rests on and forms an upward continuation of the Wa1l67. Between the walls 96 and 97 a division wall 98 is afforded which rests on the walt 68 and forms an upward continuation thereof; and similarly, a wall 99 Vis afforded so as to rest on and form an upward continuation thereof. k The side wall 95 is arranged in the present instance to afford an intake passage or opening 95A through which outside air may enter to pass downwardly through the passage 28D, and the top of the unit 24 between the walls 95 and 96 is in this instance closed by a top wall 100. Between the walls 97 and 99 the top wall 100 has a discharge opening 28-2 from which such outside air may be discharged after use. Similarly, the top wall 100 closes the upper side of the unit 24 between the walls 96 and 98, while a discharge opening 25-2 for the inside air circuit is afforded in the wall 100 between the walls 97 and 98. The side wall 96, in the form shown, has an intake opening 96A formed herein to which the return pipe of the ductwork may be connected. Within the passage 25D and in the space between the walls 96 and 98, an air filter 101 is preferably positioned to filter the air passing through the inside air system. The inlet opern'ngs for the inside and outside air intake passages may, if desired, be provided in the top wall 100, as indicated in dotted outline at 295A and 296A in Fig. 3, and in such an instance the corresponding intake opening 95A or 96A, or both, would be eliminated through the provision of imperforate side walls 975 and 96.

Within the inside air passage 25U^and disposed aboveY the heat exchanger 27, an electric booster heater is mounted so that this heater may be rendered operative when additional heat beyond the normal capacity of the system is required, or during the defrosting cycle that will be described hereinafter.

The water level in the sump 33 is maintained at -a constant level through the provision of a water supply line 107 and a fioat control valve 108 which, with its controlling fioat 1081-?, is mounted on the lower surface of the pump support platform. The sump 33 is also provided with an overflow 109.

The sump 33 is arranged to receive and collect condensate -that may be formed on any one of the heat exchangers 26 to 30, and for this reason a drip pan 110 is mounted in the outside fan chamber 49 beneath the support 53B, while a similar drip pan 111 is mounted in the inside fan chamber 50 beneath the supports 52B. These drip pans slope toward the sump 33 and are arranged to discharge the collected water into the sump.

Within the inside air passage 25, and associated with the sump 33, is an upstanding humidifier plate of an absorbent material, having a wick-like action, and this plate is mounted so that its lower edge is ydisposed in the sloping portion of the sump 33 below the normal water line that is maintained therein` The humidifier plate 115 extends upwardly for a substantial distance into the charnber 49 so as to be subjected to air flow, and is notched at 115N along its lower edge to afford clearance for the fan supporting bars 52B, The humidifier plate 115 attains its humidifying action in such a way as to afford the de sired humidity in the inside air circuit within a range varia-y tion that is satisfactory in many instances. Under other instances, however, it may be desirable to attain a more accurate regulation of humidity, and in such an instance, the wall sections 68W in the inside air circuit are constituted in the form of pans to which a constant but relatively small supply of water is supplied, and the control of humidity is attained through the association of an intermittently operable electric heater 115H with each of the pans 68W. The manner of control of the heaters 115H will be described in some detail hereinafter. It should be pointed out that any excess water that may be supplied to the pans 68W merely overflows onto the drain pan 111 so as to be discharged into the sump 33.

The enclosed compressor means Before describing the refrigerating circuit in detail, it should be pointed out that under the present invention the compressors C'l and C2 are fully enclosed in a sound and heat insulated compressor chamber 80, and this chamber is so constructed that there can be no appreciable air flow either into or out of the chamber. With this arrangement, and through the use of the heat exchanger 35, the heat of the compressors is utilized under the present invention to contribute a portion of the heat that is required in the inside air system and, as will be further explained, the heat exchanger 85 in this arrangement serves as a super heater for the return refrigerant as it approaches the compressor so as to improve the performance of the compressors.

The refrigerant circuits The 4-way valve 84 is of a well known type, and serves as the primary governing means for determining the flow path of the refrigerant in the present system. This 4- way valve is actuated between its two positions by means of a pilot valve 84P, which is shifted between its two effective positions by means of a solenoid 84S, and the way in which this solenoid is controlled will be described hereinafter.

The refrigerant that is being returned to the compressors C1 or C2 flows from the 4-way valve 84 through a line 118 to one end of the superheater 85, and any liquid components of the refrigerant that are thus fed to the superheater 85 are evaporated within the superheater and pass to a suction line 119 that has branches 119-1 and 119-2, which convey the low pressure gaseous refrigerant to the respective compressors C1 and C2. The refrigerant gas is compressed within one or the other, or both, of the compressors, the suction pressures of which are equalized by an equalizing line 129. Compressor discharge is fed through high pressure lines 121-1 and 121-2 to a common hot gas line 121 that extends to the 4-way control valve 84. In one setting of the 4-way valve 84, this hot gas is fed through a line 122 to the upper or intake header 30-1 of the heat exchanger 30.

As it passes through the heat exchanger 30, the gas is subjected to a condensing action, and passes to a common header 29-30H which constitutes the lower header for the heat exchanger 30 and the upper header for the heat exchanger 29. The gaseous and condensed portions of the refrigerant then ow to a lower header 29-2 of the heat exchange unit 29, and pass through a pipe 124 to a 3-way hand valve 123 and to a line 125. This line includes a check valve 130, a lter-dryer unit 131 and an expansion valve 132, from which the expanded gas Hows to a 3-way hand valve 133 and through a pipe 134 to the lower header 26-2 of the heat exchange unit 26. The expansion valve 132 is controlled in a conventional manner by a control element 132C that is associated with the return or suction line 118 (see Fig. 7). The refrigerant that is thus supplied to the heat exchanger 26 passes through this heat exchanger and a common header 26-27H to the lower end of the heat exchange unit 27, andfin passing through the unit 27, the evaporation is substantially completed and the gaseous refrigerant and the remainingA unevaporated portions thereof pass into an kpressure position.

upper header 27-1 of the unit 27 and through a return pipe to the 4-way valve 84. The action of the system in the summer setting thereof is therefore to cool the air passing through the inside air passage 25.

In the winter setting of the 4-way valve 84, the hot gases under pressure from the compressors pass through the line 135 and through the heat exchange units 27 and 26 in succession, so that the hot gas is condensed, and since this condensing action is obtained by air flow through the inside air passage 25, this serves to heat the air in the inside air system. The condensed refrigerant then passes through the line 134 and the hand Valve 133, but since it cannot ow through the check valve 130, this condensed or liquid refrigerant is transmitted through a line 136, a check valve 137, a filter-dryer unit 138, an expansion valve 139 and a pipe 140 to the 3-way valve 123 from which it passes through the line 124 to the lower header 29-2 of the heat exchange unit 29. This refrigerant then passes through the heat exchange units 29 and 30, and since for winter operation the system is set, as will hereinafter be described, so as to supply such liquid refrigerant to the heat exchangers 29 and 30 at a temperature which is iifteen to twenty degrees below the minimum outside air temperature, the refrigerant will absorb heat from the air flowing through the outside air system of the apparatus. This is effective to evaporate a large proportion of the refrigerant, and this evaporated refrigerant, along with the entrained unevaporated portions thereof, will pass through the line 122 to the 4-way control valve 84 which in this winter setting transmits the refrigerant to the suction line 11S and the superheater S5 so that after superheating, the gaseous refrigerant is returned to the intake of the compressor through the line 119. The expansion valve 139 is governed in a conventional manner by a control unit 139C that is associated with the suction line 11S adjacent to the control unit 132C.

The pilot valve 84? has a control connection 84-1 to the main valve 84, and pressure connections for the pilot valve 841) are afforded by pipes 84-2 and 84-3 extended respectively to the return line 118 and the high pressure line 121-1.

The pressure operated controls For control purposes that will be described in further detail hereinafter, a high pressure control line 142 is extended from the high pressure line 121-1, and has a pressure operated high limit switch 143 associated therewith. The line 142 also has a pressure operated switch 144 connected thereto for the purpose of controlling the inside fan 52, as will be described. A pressure operated switch 145 is also associated with the high pressure line 142 for the purpose of controlling the pump 51 that supplies water to the evaporative condenser, and this action will be described hereinafter,

A low pressure control line 146 is connected to the intake of the compressor C-2 so as to be thereby associated with the suction line 119, and this low pressure line 146 has a pressure switch 147 associated therewith that is effective to control the operation of the secondary compressor C-Z so as to start the compressor C-2 when the return line pressure is reduced to such a level as to indicate the need for added compressor capacity in the system.

A third control pressure line 14S is connected to the gas line 122 and this line is utilized to govern the operation of a pressure switch 149 which, in turn, serves as a primary control for governing the automatic defrosting operation of the system. The pressure switch 149 is of the snap acting type arranged at an adjustably set low pressure to snap to its low pressure position, and at an adjustably set high pressure position to snap to its high The pressure switch 149 is connected to the line l148 through a check valve 150 and a spring biased relief valve 151 connected in parallel, the check valve 150 being arranged to permit flow of gas from the pressure switch 149 to the line 148, while the relief valve 151 is an adjustable spring-loaded valve arranged to prevent tlow of gas from the pressure switch 149, and to allow flow of gas to the pressure switch 149 when the pressure of such gas in line 148 reaches a predetermined value, and the relationship of the snap acting pressure switch 149, the check valve 150 and the relief valve 151 is utilized to govern the starting time and length of the defrosting cycle and the pressure settings of the switch 149 and the relief valve 151 will be described hereinafter as they are related to each other and to the refrigerant circuits attaining this result.

The pressure switches just described are included in the main electrical controlcircuit of the system, as will now be described.

The electrical control circuits The electrical power for operating and controlling the present system is illustrated in Fig. 9 as being aiorded by a 220 volt 60 cycle l-phase circuit having a common wire 160 and two other wires 161 and 162. The compressor is arranged to be energized through a magnetic contactor CAS, while the compressor C-2 is arranged to be controlled by a magnetic contactor C-2S, and these two contactors are connected to the 220 volt l-phase circuit in a conventional manner, as illustrated in Fig. 9. Similarly, the motor for the outside air fan 53 is controlled by a magnetic contactor 53S, while the motor for the inside fan 52 is governed by a magnetic contactor 52S, and these contactors are connected to the 220 volt lphase circuit in the conventional manner. Another contactor 105S is also afforded for controlling the inside air heater 105, and this contactor is also connected in a conventional manner.

The magnetic contactors and the heater 115H constitute the primary elements that must be governed and controlled in the automatic operation of the present system, and such control is attained through a low voltage control circuit that obtains its low voltage from a transformer 163, the primary of which is connected between the wires 160 and 161. The secondary of the transformer is connected to leads 164 and 165 between which the various control circuits are disposed.

The primary setting control for the present system is alorded by a 4-position rotary switch 166 that has its common contact connected to the wire 164 by a wire 167. The settable contact for the switch 166 is afforded by a cross bar 166M that may be set in any one of four positions. In addition to the o position, the switch has an on position, a winter position indicated by the letter W and a summer position indicated by the letter 5. In the winter position, the movable contact 166M extends circuit from the wire 167 to two opposite W contacts, and from the upper one of these W contacts wires 168 and 169 extend in series to one end of a relay coil 170C, the other end of which is connected by a wire 171 to the wire 165. Wires 172 and 173 extend from the wire 169 respectively to the on position and the summer position so that when the cross bar 166M is in either the on position, the winter position or the summer position, the coil 170C will be energized. The other stationary W contact of the switch 166 is connected by a wire 174 to a terminal 17 5, and between this terminal 175 and the wire 165, a relay coil 176C is connected. Similarly, a relay coil 177C and a relay coil 178C are connected in parallel between the terminal 175 and the wire 165. Thus, in the winter position of the switch 166, the coils 176C, 177C and 178C will be energized, and this is in addition to the energization of the coil 170C.

Also connected in the low voltage circuit are the main sensing controls that sense conditions in the conditioned space for governing the operation of the system. Thus, a main thermostat 180 is connected between the wire 164 and a terminal 181, and relay coils 182C, 183C and 184C are connected in parallel between'the terminal 181 and the wire 165. Thus, upon closure of the main thermostat 180, these three relay coils will be energized. A humidistat 18S is also connected at oneA of its terminals to the wire 164, and between the other lterminal of the humidistat the wire 165, a relay coil 186C is connected so that this coil will be energizedlwhen sensing of the need for humidiiication causes the humidistatto close. A secondary or sub-thermostat 188 is connected at one of its terminals to the wire 164 and from the other terminal of the secondary thermostat 188, a relay coil 187C is connected to the wire 165. The thermostats 180 and 188 are of the type which close their contacts upon a drop in temperature to a predetermined level, and such thermostats may be of any conventional type arranged to afford a working differential whereby the thermostat opens circuit at a slightly high temperature level. The thermostat 180 is mounted in the usual position on an inside wall of the building that is being conditioned, while the sub-thermostat 188 is mounted on the inside surface of an outside wall and near the floor of a room. The location of the sub-thermostat 188 is preferably on the outside where the greatest heat loss may be expected, and the thermostat 188 is set about 5 degrees below the setting of the thermostat 180 so'as to attain a highly advantageous heat control in Winter, as will be explained.

The relay coils that have thus been described serve to control correspondingly numbered relays shown in Fig. 9 which, in turn, govern the energizing coils of the dilerent magnetic contactors.

Conditioning relays 170, 176, 177 and 178 are provided which are under control respectively of the relay coils 170C, 176C, 177C and 178C, and all four of these relays are of the single pole double throw type, and are arranged so that the contact bars thereof are disposed normally in the lower position shown in Fig. 9 and are actuated to their upper position when their respective coils are energized. A wire 190 extends from the wire 162 to one.r of the upper contacts of the relay 170, while a Wire 191 extends from the other upper contact of the relay 170, and has branch leads extended therefrom to one upper and one lower contact of each of the relays 176 and 177. The other lower contact of the relay 177 is connected by a wire 193 to one end of the operating coil 52C of the magnetic contactor 52S of the inside fan 52. Thus, when the relay 170 is energized and the relay 177 is deenergized, the inside fan 52 will be operated, and this condition prevails when the main control switch 166 is in its on position. Y

The other upper contact of the relay 177 is connected by a wire 194 to one contact of the pressure operated switch 144, the other contact of which is connected by a wire 194B to the wire 193. Thus, when the relay 177 is in its upper or winter position, and the conditioning relay 170 is in its upper or winter position, the inside fan is placed under control of the pressure switch 144. With this arrangement, thev inside fan remains inoperative until pressure in the compressor output line 121-1 reaches a predetermined operative level so as to close the v pressure switch 144.

The other conditioning relay 178 s connected by a wire 195 to the line wire 162, and -this wire 195 has branches extending to one bottom contact of therelay 178. The other bottom contact of the relay 178 is connected by a wire 196 to one contact of the pressure switch 145, and the ywire 197 extends from the other contact of the switch 145 to one terminal of the motor 51M, the other terminal of this motor being connected to the common line wire 160. The actuation of the relay 178 to its upper or winter position renders the circuit to the motor 51M ineffective, but when the relay 178 is deenergized and its common contact is in its lower position, the pump circuit is conditioned for operation under conf trol of the pressure switch y145. ,This presstue switchis arranged to close when pressure in the output line 121-1 of the refrigerant circuit becomes too high, and this causes the pump 51M to pump water through the spray, thus to cause the condenser 29 to operate as an evaporative condenser.

Control relays 182 and 184 are also provided in the control circuit, and these relays are of the single pole double throw type, and are controlled respectively by the relay coils 182C and 184C. One upper contact of the relay 182 is connected by a wire 198 and a wire 199 to the other upper contact of the conditioning relay 176, and the wire 199 has an extension 199B that extends to the common contact of the pressure switch 149. The other upper contact of the relay 182 and the corresponding lower contact thereof are connected by wires 200 and 201 in series to one contact of the normally closed safety or overload pressure switch 143, the other contact of which is connected by wire 202 to a terminal 203. From this terminal, a' wire 204 extends to one contact of a normally closed thermostatic overload switch 205 that is located in the compressor C-1, and the other contact ofA this switch is connected by a contact 206 to one terminal of an operating coil CISC that constitutes the operating coil of the magnetic contactor CIS that governs the compressor C-l. The other terminal of this coil is connected to the common line wire 160.

From the terminal 203, a `wire 207 is connected to corresponding upper and lower contacts of a conditioning relay 183 that is governed by the relay coil 183C. The other upper contact of the relay 183 is connected by a wire 208 to the low pressure contact of the pressure switch 147, and a wire 209 extends from the common Contact of the switch 147 to one stationary Contact of a time delay relay 210. The other stationary contact of this relay is connected by a wire 211 to a thermostatically operated normally closed safety switch 212 that is included in the compressor C-2 and the wire 213 extends from the other contact of this safety switch to an operating coil C2SC that serves as the operating coil for the magnetic contactor C2S. The other terminal of this operating coil is connected to the common line wire 160. The time delay relay 210 has an operating coil 210C connected across the two stationary contacts of this relay, and the operation is such that the relay 210 is closed only after a predetermined period, thus to avoid concurrent starting of the two compressors.

The other stationary contact of the pressure operated switch 147 is connected by a wire 214 to the other lower con-tact of the relay 183, and thus the switch =147 causes operation of the second compressor in response to low pressure in the suction line 119 during the winter operation of the system, and in reponse to high pressure in the line 119 during summer operation of the system.

rl'he other lower contact of the control relay 182 is connected by wires 220 and 221 to the other lower contact of the conditioning relay 176, and a branch lead 222 extends from the wire 221 to one lower contact of the control relay 184. The other lower contact of the relay 184 and the corresponding upper contact thereof are connected by a wire 223 to one terminal of the operating coil 53SC, which serves to operate the magnetic contactor 53S that controls the outside fan 53. The other terminal of the coil 538C is connected to the line wire 160. The other upper contact of the relay 184 is connected by a wire 224 to the high pressure stationary contact of the pressure operated switch 149, and a wire 225 connects this same contact to one terminal of the operating coil 84S of the magnetic pilot valve 84, the other terminal of this operating coil being connected to the wire 160. The other or low pressure stationary contact of the switch 149 is connected by a wire 227 to a terminal 228, and this terminal 228 is afforded in the control circuit for the inside air heater 105. This inside air heater circuit may be completed by movement of the pressure switch 149 to its low pressure position, or through closure of the secondary of sub-thermostat 188, and for obtaining control in response to the operation of such thermostat, a relay 187 which is controlled by the coil 187C. Thus, a wire 230 extends from the Wire 199B to one stationary contact of the relay 187, and a wire 231 extends from the other contact of this relay to the terminal 228. From the terminal 228, a wire 232 extends to one stationary contact of a normally open holding switch 233 that is arranged to be moved to its closed position as an incident to the operation of the magnetic contactor C-1S. A wire 234 extends from the other stationary contact of the switch 233 to one contact of a flow switch 235 that is normally open and is arranged to be closed by air flow in the inside air passage 25. A wire 236 extends from the other contact of the flow switch 235 to one terminal of an operating coil SC of the magnetic contactor 105s, the other terminal ofthis coil being connected to the wire 160. Thus, when the circuit is closed by the switch 149 or by the relay 187, the inside air heater 105 will be effective, it being understood, of course, that such operation can take place only when the conditioning relay 176 is in its upper or winter position.

The heater H that is included in the humidifier has one terminal connected by a wire 240 to the line wire and the other terminal of the heater is connected to one station-ary contact of a normally open Irelay 186 that is arranged to be closed by operation of the operating coil 186C. The other stationary contact of the relay 186 is connected by a wire 241 to one stationary contact of a holding switch 242 that is normally open and which is arranged to be closed as lan incident to the operation of the magnetic contactor 52S. A wire 243 extends from the other contact of the switch 242 to the line wire 162. Conventional circuit breakers, as shown, are used in tfhe usual manner to protect all motors and branch lines.

Operation The operation of the system hereinabove described is set forth in detail in my .copending :application Serial No. 389,640, filed November 2, 1953, and reference is hereby made to such application in respect to such operation. With regard to the housed compressor means of the present invention it should be observed that the insulation of the closed compressor chamber 80 serves to reduce the audible compressor noise to an unobjectionable level so as to obviate this common objection to conditioning systems of this general type. Moreover, the compressor heat which is confined to the compressor chamber 80 by the insulated walls thereof is transferred to the refrigerant by the superheater 85, thus to improve the compressor performance :and eiectually utilize the compressor heat in accomplishing the heating function of the apparatus.

Concl uson From the foregoing description, it will be evident that alterations as fall Within the purview of the following claims.

I claim:

1. In an air to air heat pump Iapparatus having inside and outside air-circulating passages and a refrigerating system with heat exchangers in sai-d outside and inside ai-rcirculating passages for a winter heating cycle, means affording a fully closed heat and sound insulated compressor chamber, compressor means forming part of said refrigerating system and mounted and housed within said chamber, and a nned superheater forming'part of said refrigerating system and mounted on the refrigerant suction line thereof, said superheater being located in said compressor chamber to heat expanded refrigerant and thereby utilize the compressor heat in the heating cycle of the heat pump apparatus.

2. In an air to air heat pump apparatus having inside and outside air-circulating passages and a refrigerating system including compressor means and having heat exchangers in said outside and inside air-circulating passages for a winter heating cycle, means aording a fully closed heat and sound insulated compressor chamber, said compressor means being mounted and housed Within said chamber, and a superheater forming part of said refrigerating system and located in the refrigerant suction line thereof and disposed in the upper part of said compressor chamber in spaced relation above said compressor means to heat expended refrigerant and thereby utilize the compressor heat in the heating cycle of the heat pump apparatus.

3. In heat pump apparatus, a refrigerating system having compressor means, heat exchangers and means for reversing refrigerant flow in the system for selectively heating or cooling of a space to be conditioned, means affording a fully enclosed heat and sound insulated compressor chamber, said compressor means being mounted in and housed in said compressor chamber, and a superheater located in said chamber and included in the refrigerant suction line of said system to utilize the compressor heat in the heating cycle of said system and cool said compressor chamber in both the heating and cooling cycles of the system. Y

4. In heat pump apparatus, a refrigerating system having compressor means, heat exchangers and valve means for reversing refrigerant flow in the system yfor selectively heating or cooling of a space to be conditioned, means affording a fully enclosed heat and sound insulated compressor chamber, said compressor means being mounted and housed in said compressor chamber, and a nned superheater located in an upper portion of said compressor chamber and mounted on the refrigerant suction line of said system leading from said valve means to said compressor means to heat expended refrigerant and thereby to utilize the compressor heat and increase the useful output in the heating cycle of said system and to cool said compressor chamber in both the heating and cooling cycles of the system.

References Cited in the file of this patent UNITED STATES PATENTS 634,335 Glasson Oct. 3, 1899 1,548,517 Dubrovin Aug. 4, 1925 2,093,496 Van Degrift Sept. 21, 1937 2,181,213 Smith Nov. 28, 1939 2,215,534 Smith Sept. 24, 1940 2,249,882 Buchanan July 22, 1941 2,388,314 Eisinger Nov. 6, 1945 2,420,442 Rataiczak May 13, 1947 2,608,834 McCloy Sept. 2, 1952 

